"Icest" is not a valid spelling in English. The closest word in pronunciation is "iced," which is spelled with the IPA phonetic transcription /aɪst/. The "i" in "iced" makes the long "i" sound, and the "c" and "e" together create the "s" sound. Without context or a specific language in mind, "icest" does not correspond to any recognizable word or sound combination in English.